The introduction of an immersion fluid in contact with the resist-coated substrate is, from the perspective of the resist material, a significant departure from the conventional lithographic process. The impact of this modification on the lithographic imaging materials is as yet only poorly characterized. We report the results of studies aimed at an improved understanding of how immersion in water during exposure influences the functional properties of films of lithographic materials. We have evaluated the water permeability of candidate immersion topcoat materials; the role of immersion topcoat materials in reducing airborne contamination and water-resist interactions; the impact of water immersion on image blur in chemically amplified resists; and high-resolution imaging of candidate immersion resist materials under conditions of poor aerial image contrast. Analytical techniques such as QCM and reflectance analysis of thin films, DUV interferometric immersion lithography, and trace organic analysis are applied in this work.